High efficiency aspirator for inflatable emergency slides

ABSTRACT

An aspirator assembly for inflating an emergency slide is disclosed. The aspirator assembly includes a bell housing, a mixing chamber, and a nozzle assembly. The bell housing includes a ring defining an inlet port at which a check valve is located and into which ambient air can flow. The mixing chamber has an outlet port, The nozzle assembly is located in the mixing chamber and includes plural passageway sections defining concentric rings and cross bars. The passageway sections include internal passageways in communication with plural nozzle jets through which a compressed air is introduced into the mixing chamber to mix with the ambient air. The passageway sections are of an airfoil shape cross-section having a rounded leading end directed towards the inlet port and a trailing end is directed toward the outlet port to reduce air turbulence within the mixing chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims the benefit under 35 U.S.C. §119(e) of Application Ser. No. 62/529,094 filed on Jul. 6, 2017 entitledHIGH EFFICIENCY ASPIRATOR FOR INFLATABLE EMERGENCY SLIDES and whoseentire disclosure is incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK

Not Applicable

FIELD OF THE INVENTION

This invention relates generally to devices for inflating inflatabledevices, and more particularly to aspirator assemblies configured forthe rapid inflation and deployment of inflatable structures, e.g.,evacuation slides, rafts and the like.

BACKGROUND OF THE INVENTION

Many inflation systems are currently available for effecting the rapidinflation of emergency evacuation slides and life-rafts. Such inflationsystems typically make use of an aspirator assembly into which apressurized primary gas, e.g., compressed air, is rapidly introducedthrough a multi-port nozzle to induce ambient air to be drawn into ahollow chamber in the aspirator assembly via an air-inlet port of theaspirator assembly, whereupon the two gasses combine and flow to adischarge or outlet port of the aspirator assembly. The inlet portincludes a check valve, which is automatically opened upon the creationof a partial vacuum in the hollow chamber of the aspirator assembly. Theoutlet port is in fluid communication with the hollow chamber and iscoupled to the structure to be rapidly inflated, e.g., an aircraftevacuation slide, such that the combined gasses exiting the outlet portrapidly inflate the slide. In particular, the rapid introduction of thepressurized primary gas into the nozzle assembly creates a ventureeffect adjacent the nozzle jets to produce result in partial vacuumwithin the aspirator assembly chamber. That partial vacuum causes thecheck valve at the inlet port to open, whereupon ambient air enters intothe chamber. When inside the chamber the ambient air mixes with theprimary gas in a mixing region of that chamber to generate a combinedair-gas flow mixture, which exits the outlet port which is coupled to,e.g., disposed within, the inflatable slide or other structure to beinflated. Thus, the aspirator assembly uses a small volume of compressedair (or other gas) to entrain a relatively large volume of ambient airto inflate an inflatable structure, with the efficiency of the aspiratorassembly being expressed by its what is termed its “mass-flow ratio”(the ratio of the volume of primary gas to the volume of ambient airentrained by the aspirator assembly).

The patent literature includes various patents directed to devices foreffecting the inflation of evacuation slides, e.g., U.S. Pat. No.3,598,504 (Siravo); U.S. Pat. No. 3,840,057 (Lesh, Jr.); U.S. Pat. No.4,368,009 (Heimovics, Jr., et al.); U.S. Pat. No. 6,004,176 (Moran); andU.S. Pat. No. 8,066,493 (Renz et al.)

While prior art aspirator assemblies for effecting the inflation ofevacuation slides and the like are generally suitable for their intendedpurposes, they nevertheless leave something desired from the standpointof efficiency or mass-flow ratio. As such, a need exists for anaspirator assembly which is more efficient than the prior art and hencecan inflate an inflatable structure more quickly than the prior art. Thesubject invention addresses that need.

All references cited herein are incorporated herein by reference intheir entireties.

SUMMARY OF THE INVENTION

One aspect of this invention is an aspirator assembly for inflatinginflatable emergency evacuation devices. The aspirator assemblycomprises a bell housing, a mixing chamber and a nozzle assembly. Thebell housing forms a proximal end of the aspirator assembly and includesan ambient air inlet port at which a check valve is located. The checkvalve is configured to enable ambient air to enter the ambient air inletport when the check valve is open. The mixing chamber has a distalportion that includes an outlet port. The mixing chamber is connected tothe bell housing and defines a gas flow path between the inlet port andthe outlet port. The gas flow path extends along a central longitudinalaxis. The outlet port is configured to be coupled to an emergencyevacuation inflatable device. The nozzle assembly is located in themixing chamber and comprises a primary gas inlet port and a plurality ofpassageway sections. The passageway sections have internal passagewaysin fluid communication with the primary gas inlet port. The passagewaysections include plural nozzle jets extending in a direction toward theoutlet port. The passageway sections are of a generally symmetricalcambered top and bottom airfoil shape cross-section comprising a roundedleading end and a tapering trailing end. The leading edge is directedtowards the inlet port. The trailing edge is directed toward the outletport, whereupon pressurized primary gas introduced into the primary gasinlet port flows through the internal passageways to the nozzle jetsfrom which it exits, thereby producing a venturi effect and partialvacuum adjacent the nozzle assembly within the mixing chamber to causethe check valve to open, whereupon ambient air is drawn into the mixingchamber and around the nozzle assembly to the outlet port. The generallysymmetrical cambered top and bottom airfoil shape cross-sectional shapeof the passageway sections serving to reduce turbulent flow of ambientair around the nozzle assembly.

In accordance with one preferred aspect of the aspirator assembly ofthis invention, each of the nozzle jets is a tubular member.

In accordance with another preferred aspect of the aspirator assembly ofthis invention, each of the nozzle jets includes an open free end and asidewall tapering in thickness toward the free end.

In accordance with another preferred aspect of the aspirator assembly ofthis invention, plural ones of the passageway sections conjoin with eachother to form at least one ring-like structure.

In accordance with another preferred aspect of the aspirator assembly ofthis invention, plural ones of the passageway sections conjoin with eachother to form a first elongated linear structure, and plural ones of thepassageway sections form a second elongated linear structure, the firstelongated linear structure extending perpendicularly to the secondelongated linear structure.

In accordance with another preferred aspect of the aspirator assembly ofthis invention, the passageway sections are located in a plane extendingperpendicularly to the central longitudinal axis.

In accordance with another preferred aspect of the aspirator assembly ofthis invention, the first elongated linear structure includes an endportion at which the primary gas inlet port is located.

In accordance with another preferred aspect of the aspirator assembly ofthis invention, the bell housing comprises a ring, a pair of resilientflap sections, and a support member. The ring has an outer surface and agenerally planar undersurface. The undersurface forms a valve seat. Thesupport member mounts the flap sections immediately adjacent the ring sothat the flap sections are normally in engagement with the valve seat,but which flex upon the existence of the partial vacuum within themixing chamber to move off of the valve seat.

In accordance with another preferred aspect of the aspirator assembly ofthis invention, the outer surface of the ring is a rounded convexsurface.

In accordance with another preferred aspect of the aspirator assembly ofthis invention, the resilient flap sections comprise a unitary basemember of circular profile and a pair of almost semi-circular sections.The base member has a pair of grooves. Each of the grooves forms arespective flexure line. Each of the almost semi-circular sections has alinear edge and is secured to the base section, with the linear edgebeing located immediately adjacent a respective one of the flexurelines.

In accordance with another preferred aspect of the aspirator assembly ofthis invention, the ring includes a central opening and wherein thesupport member comprises a bar-like member secured within the opening,the base member is fixedly secured to the support member between theflexure lines.

Another aspect of this invention is a nozzle assembly for use in anaspirator assembly for inflating inflatable emergency evacuationdevices. The aspirator assembly has a proximal end including an ambientair inlet port and a check valve, a mixing chamber, and a distal endhaving an outlet port. The mixing chamber defines a gas flow pathbetween the inlet port and the outlet port. The nozzle assembly has alongitudinal axis and comprises a primary gas inlet port, and aplurality of passageway sections. The passageway sections have internalpassageways in fluid communication with a primary gas inlet port forreceipt of a pressurized primary gas. The passageway sections includeplural nozzle jets extending in a first direction parallel to thelongitudinal axis. The passageway sections are of a generallysymmetrical cambered top and bottom airfoil shape cross sectioncomprising a rounded leading end and a tapering trailing end. Theleading end is directed in a second direction opposite to the firstdirection. The trailing end is directed in the first direction. Thenozzle assembly is configured whereupon pressurized primary gasintroduced into the primary gas inlet port flows through the internalpassageways to the nozzle jets from which it exits.

In accordance with one preferred aspect of the nozzle assembly of thisinvention, each of the nozzle jets is a tubular member.

In accordance with another preferred aspect of the nozzle assembly ofthis invention, each of the nozzle jets includes an open free end and asidewall tapering in thickness toward the free end.

In accordance with another preferred aspect of the nozzle assembly ofthis invention, plural ones of the passageway sections conjoin with eachother to form at least one ring-like structure.

In accordance with another preferred aspect of the nozzle assembly ofthis invention, plural ones of the passageway sections conjoin with eachother to form a first elongated linear structure, and plural ones of thepassageway sections form a second elongated linear structure. The firstelongated linear structure extends perpendicularly to the secondelongated linear structure.

In accordance with another preferred aspect of the nozzle assembly ofthis invention, the passageway sections are located in a plane extendingperpendicularly to the central longitudinal axis.

In accordance with another preferred aspect of the nozzle assembly ofthis invention, the first elongated linear structure includes an endportion at which the primary gas inlet port is located.

Still another aspect of this invention is a bell housing for use in anaspirator assembly for inflating inflatable emergency evacuationdevices. The aspirator assembly comprises a mixing chamber, a nozzleassembly, and a distal end having an outlet port. The mixing chamberdefines a gas flow path between an inlet port and the outlet port. Thenozzle assembly is configured to introduce a pressurized primary gasinto the mixing chamber. The bell housing is configured to form a checkvalve for an inlet port of the aspirator assembly and comprises a ring,a support member and a pair of resilient flap sections. The ring has anouter surface and a generally planar undersurface. The undersurfaceforms a valve seat. The pair of resilient flap sections are mountedimmediately adjacent the ring by the support member, whereupon the flapsections are normally in engagement with the valve seat, but which flexupon the existence of a partial vacuum within the mixing chamber to moveoff of the valve seat.

In accordance with one preferred aspect of the bell housing of thisinvention, the outer surface of the ring is a rounded convex surface.

In accordance with another preferred aspect of the bell housing of thisinvention, the resilient flap sections comprise a unitary base member ofcircular profile and a pair of almost semi-circular sections. The basemember has a pair of grooves. Each of the grooves forms a respectiveflexure line. Each the almost semi-circular sections has a linear edgeand is secured to the base section, with the linear edge being locatedimmediately adjacent a respective one of the flexure lines.

In accordance with another preferred aspect of the bell housing of thisinvention, the ring includes a central opening and wherein the supportmember comprises a bar-like member secured within the opening. The basemember is fixedly secured to the support member between the flexurelines.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is an isometric view of one exemplary embodiment of an aspiratorassembly for inflating an inflatable emergency slide, e.g., an aircraftevacuation slide;

FIG. 2 is an isometric view similar to FIG. 1, but showing the exemplaryembodiment of FIG. 1 from the opposite side;

FIG. 3 is an is isometric view similar to FIG. 1, but with a portion ofthe aspirator assembly omitted so that a nozzle assembly which islocated within the aspirator assembly can be readily seen;

FIG. 4 is an enlarged isometric view of the nozzle assembly shown inFIG. 3;

FIG. 5 is an isometric view similar to FIG. 4, but taken from theopposite side of the nozzle assembly:

FIG. 6 is an enlarged sectional isometric view of the nozzle assemblytaken along lines 6-6 of FIG. 5;

FIG. 7 is an enlarged front elevational view of the nozzle assemblyshown in FIGS. 3-6;

FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG. 7;

FIG. 9 is a slightly reduced side elevational view taken along line 9-9of FIG. 7;

FIG. 10 is a slightly reduced side elevational view taken along line10-10 of FIG. 7;

FIG. 11 is an enlarged sectional view taken along line 11-11 of FIG. 7;

FIG. 12 is an enlarged isometric view of the proximal end of theaspirator assembly shown in FIG. 1, illustrating the ingress of ambientair into the bell housing of the aspirator assembly during itsoperation;

FIG. 13 is an enlarged exploded isometric view of the components makingup the bell housing shown in FIG. 12;

FIG. 14 is an enlarged exploded isometric view of the components makingup the bell housing shown in FIG. 12, but taken from an oppositedirection; and

FIG. 15 is another enlarged exploded isometric view of the componentsmaking up the bell housing shown in FIGS. 13 and 14, with some of thosecomponents shown in their assembled state.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings wherein like characters refer to likeparts there is shown at 20 in FIG. 1 one exemplary embodiment of anaspirator assembly constructed in accordance with this invention. Theaspirator assembly 20 is configured so that it can be used in a similarmanner to prior art aspirator assemblies to effect the rapid inflationof emergency evacuation slides, life-rafts or other inflatable emergencyevacuation devices. However, the aspirator assembly of the subjectinvention is more efficient than prior art aspirator assemblies due tothe construction of various of its components Like prior art aspiratorassemblies, the aspirator assembly 20 of this invention basicallycomprises an aspirator body 22, a bell housing 24 and a nozzle assembly26 (FIG. 3). The aspirator body is very similar to that of the priorart, whereas the bell housing and the nozzle assembly are considerablydifferent, as will be described later.

Turning now to FIGS. 1-3, the details of the aspirator body 22 will bediscussed. As can be seen the body 22 is a hollow tubular member havinga central longitudinal axis X and is composed of a main section 28 andan extension section 30. The main section 28 comprises a sidewall ofcylindrical shape and constant diameter. The extension section 30 isfixedly secured to the main section and is also of cylindrical shape.However, the section 30 includes three portions 30A, 30B and 30C, whoserespective sidewalls are of different shapes. In particular, thesidewall of the proximal end portion 30A is cylindrical and configuredto be received within the distal end of the sidewall of the main section28 to secure the extension section to the main section. The sidewall ofthe intermediate portion 30B of the extension section is alsocylindrical, but flares outward at a slight angle with respect to thelongitudinal axis X in the distal direction from the portion 30A. Thesidewall of the distal end portion 22C of the extension section is alsocylindrical, but flares outward at a greater angle with respect to thelongitudinal axis X in the distal direction from the intermediateportion 30B. The free end of the section 30C is open and forms theoutlet port 32 of the aspirator assembly 22. As is conventional, theoutlet port 32 is configured to be located within an inflatable slide(not shown), life-raft (not shown), or other inflatable emergencyevacuation device to effect the rapid inflation thereof.

The bell housing 24 is mounted at the proximal end of the main section28 of the aspirator body 22. The details of the bell housing 24 will bedescribed later. Suffice it for now to state that the bell housing formsthe inlet port 34 of the aspirator assembly 20. A check valve 36 (FIGS.1 and 5), which forms a portion of the bell housing, and which includesa pair of flap sections 38A and 38B, is located at the inlet port 34.The check valve is configured such that when it is opened it enablesambient air to flow through the inlet port into the interior of theaspirator body. A portion of the interior of the aspirator body forms amixing chamber in which a compressed gas, e.g., air, is introduced tomix with ambient air drawn through the inlet port such that the mixedgas exits the outlet port 32 to effect the inflation of the evacuationdevice.

Turning now to FIGS. 4-11, the details of the nozzle assembly 26 willnow be described. The nozzle assembly 26 serves as the means forinjecting the compressed gas into the mixing chamber. The nozzleassembly basically comprises a concentric ring-like, cross-braced membermade up of plural conjoined passageway sections including internalpassageways and plural nozzle jets in fluid communication with theinternal passageways. In particular, as best seen in FIGS. 4, 5 and 7the nozzle assembly comprises an outer ring 40, an inner ring 42, alinear section 44, and a linear section 46. The inner ring 42 is locatedcentered within the outer ring 40. The linear sections 44 and 46intersect and extend perpendicularly to each other to serve as a crossbrace for mounting the nozzle assembly within the main section 28 of theaspirator body. To that end, the linear section 44 is composed of twocoplanar half passageway sections 44A and 44B which are conjoined toeach another. In a similar manner, the linear section 46 is composed oftwo coplanar half passageway sections 46A and 46B which are conjoined toeach other. The outer ring 40 composed of four coplanar quarter ringpassageway sections 40A, 40B, 40C and 40D which are conjoined with oneanother. Similarly, the inner ring 42 is composed of four coplanarquarter ring passageway sections 42A, 42B, 42C and 42D which areconjoined with one another.

As best seen in FIGS. 9 and 10 all of the passageway sections 40A-46B ofthe nozzle assembly lie in a common plane, which is perpendicular to thelongitudinal axis X. Each of the passageway sections 40A-46B includes aninternal passageway 48 extending therethrough, with the passageways ofeach of those passageway sections being in fluid communication with eachother. The end of the passageway 48 in the passageway section 46B formsthe primary gas inlet port of the nozzle assembly. In particular, theend portion of the passageway section 46B is in the form of an enlargedhead 50 having an internally threaded opening 52 which is internallythreaded and is configured to be connected via a conventional threadedconnector (not shown) to a source of compressed primary gas (not shown).Thus, the compressed primary gas introduced into the gas inlet port 52will flow down through all of the interconnected internal passageways 48to all of the nozzle jets.

As best seen in FIGS. 5 and 6, the end of the internal passageway 48 inthe passageway section 46A is in the form of an internally threadedopening 54. The internally threaded opening 54 is configured to receivea threaded fastener (not shown) for mounting the nozzle assembly 22within the main section 28 of the aspirator body. The ends of thepassageways 48 in the passageway sections 44A and 44B are also each inthe form of an internally threaded opening 54 that is configured toreceive a respective threaded fastener (not shown) for mounting thenozzle assembly 22 within the main section 28 of the aspirator body.

Each of the conjoined passageway sections 40A-46B includes at least onenozzle jet 56. Thus, as best seen in FIG. 7 the nozzle jets of the outerring 40 are equidistantly spaced in a circle from one another. Thenozzle jets of the inner ring 42 coupled with the nozzle jets of thelinear section 44 are also equidistantly spaced in a circle from oneanother. It should be point out at this juncture that the number andlocation of the nozzle jets can be modified if desired, depending up theapplication to which the aspirator assembly of this invention is to beput. Thus, the particular configuration and arrangement of the nozzlejets as shown and described heretofore is merely exemplary of variouspossible arrangements and configurations.

In any case, as best seen in FIG. 8, each nozzle jet is a hollow tubularmember having a central passageway 58 (Fig. lie in a plane extendingperpendicular to the longitudinal axis X. Each of the nozzle jets 34 isa tubular member having an open free end 58, and a central passageway 60extending from the passageway 48 in the associated passageway section tothe open free end. The nozzle jets extend parallel to the longitudinalaxis X and face towards the outlet port 28 of the mixing chamber whenthe nozzle assembly is mounted within the aspirator body.

The introduction of the compressed primary gas into the gas inlet port50 causes that gas to flow through the internal passageways 48 in thepassageway sections 40A to 46B and out through the open free ends 58 ofthe nozzle jets 56. That action creates a venturi effect adjacent thenozzle jets, whereupon a partial vacuum results within the mixingchamber. That partial vacuum is sufficient to cause the check valve 36to open very quickly, i.e., the ambient air pressure outside of theaspirator assembly is greater than the cracking pressure of the valve,whereupon the check valve's flap sections 38A and 38B flex inward sothat ambient air is drawn into the mixing chamber. That ambient airmixes with the compressed air exiting the nozzle jets to create an airflow path from the inlet port 34 to the outlet port 32, whereupon themixed air exits the outlet port to result in the rapid inflation of theevacuation device.

As mentioned earlier, the cross sectional shape of the passagewaysections 40A-46B of the nozzle assembly is particularly chosen to resultin optimal air flow effects adjacent the nozzle assembly as the ambientair is mixed with the compressed air in the flow path. By so doing, thenozzle assembly is able to operate more efficiently than conventionalnozzle assemblies. In particular, the cross sectional shape of thepassageway sections 40A-46B making up the nozzle assembly are all ofidentical cross sectional shape. That shape, is best seen in FIG. 11 andis a generally symmetrical cambered top and bottom airfoil shape thatcomprises a rounded leading end 62 facing the inlet port 34, and atapering trailing end 64 facing the outlet port 32. Being of an airfoillike shape there will be reduced air turbulence around the nozzleassembly. The effect of reduced turbulence renders the nozzle assemblyapproximately twenty-three percent more efficient than prior art nozzleassemblies. As will be appreciate by those skilled in the art, such anincreased efficiency will result in faster inflation of the inflatableevacuation device to which the aspirator of this invention is connected.

In accordance with one preferred embodiment of this invention, thethickness of the sidewall making up each nozzle jet 56 tapers downwardat a shallow angle, e.g., 7 degrees to the longitudinal axis of thepassageway 60, in the direction toward the free end 58 of the nozzle.This taper results in both increasing the speed at which the compressedprimary gas exits the nozzle jets, and also optimizing the amount of gasturbulence in the vicinity of the nozzle jets.

Turning now to FIGS. 12-15, the details of the bell housing 24 will nowbe described. The bell housing basically comprises housing comprises aring 66, the heretofore mentioned pair of resilient flap sections 38Aand 38B, and a support member 68. The ring includes a central openingwhich forms the heretofore identified inlet port 34, curved proximal(outer) surface 70 (FIG. 13) and a generally planar inner orundersurface 72 from which an annular wall 74 projects. The innersurface of the annular wall 74 is flush with the central opening 34. Theundersurface 76 of the annular wall forms the valve seat of the checkvalve 36. The outer surface of the annular wall is configured to fitwithin the open end of the main body section 28 of the aspirator body tomount the bell housing and the check valve thereon.

The check valve is formed of the heretofore two flap sections 38A and38B, which are mounted on respective portions of a resilient disk-shapedmember 78. The disk-shaped member 78 is configured to flex into and outof engagement with the valve seat to close and open the check valve. Tothat end the disk-shaped member 78 is formed of a resilient material,e.g., metal with a rubberized coating to create the seal with the valveseat, and is of circular profile, the outer diameter of which is equalto the outer diameter of the valve seat 76. The distal surface of thedisk-shaped member 78 includes a circular recess 80 configured toreceive the two almost semi-circular flap sections 38A and 38B. Theundersurface of the disk-shaped member 78 includes a pair of lineargrooves 82 extending across a central portion of the disk-shaped member.The grooves 82 form respective flexure or hinge lines about whichportions of the disk-like member 78 can flex. The spacing the groovesserves as connection area for mounting the disk-shaped member onto thesupport member 68. The support member 68 is a bar-like member whichincludes a planar undersurface 84 which engages the bottom surface ofthe circular recess 80 between the two linear grooves 82. Pluralfasteners (not shown) are provided to extend through holes in thesupport member 68 and the disk-shaped member to fixedly secure thedisk-shaped member to it. Each end of the support member includes anotch 86, which is configured to be received within a correspondinglyshaped slot 88 in the ring 66 to mount the support member to the ring,with the movable valve element made up by the disk-shaped member 78being located within the inlet port 34.

Each of the two flap sections 38A and 38B is of a profile which isalmost semi-circular in shape to fit within respective portions of thecircular recess 80 on either side of the support member 68. Inparticular, each flap member includes a circular portion of less than180 degrees and a linear section connecting the ends of the circularportion. The flap members are permanently secured within theirrespective portions of the circular recess 80 by any suitable means,e.g., an adhesive, and are preferably sufficiently thin so that they areflush with the top or proximal surface of the disk-shaped membersurrounding the circular recess when they are mounted therein. Due tothe natural resiliency of the material making up the disk-shaped member78, the portion of the upper (proximal) surface of that member whichsurrounds the circular recess 80 will normally be in engagement with thevalve seat and the check valve will thus be normally closed. Preferably,the flap sections 38A and 38B are formed of any suitable material toprovide some degree of rigidity to the portions of the disk-shapedmember 78 to which they are secured to ensure that there is goodengagement of the disk-shaped member with the valve seat when the valveis closed. The disk-shaped member is configured to readily flex alongthe flexure lines 82 when the cracking pressure of the check valve hasbeen exceeded, whereupon the upper surface portions of the disk-likemember surrounding the circular recess 80 move out of engagement withthe valve seat and the valve opens. That action occurs, as notedearlier, when the compressed primary gas is introduced into the nozzleassembly. The natural resiliency of the material making up thedisk-shaped member 78 will cause it to automatically flex back to itsgenerally planar state, when the air pressure within the mixing chamberis below the cracking pressure of the check valve. This action isimportant, since once the aspirator assembly of this invention hasinflated the inflatable evacuation device and the source of thecompressed primary gas shut off, the valve should quickly close toprevent deflation of the inflatable evacuation device.

As should be appreciated by those skilled in the art, the rounded orarcuate shape of the outer (proximal) surface 70 of the ring 66, and therounded or arcuate shape of the outer (proximal) surface of the supportmember, results in less air turbulence at the inlet port. That actionalso increases the efficiency of the aspirator assembly of thisinvention. In this regard, those portions of the bell housing enable anincrease in efficiency of approximately seven percent. Thus, the bellhousing constructed in accordance with this invention, when used inconjunction with a nozzle assembly constructed in accordance with thisinvention can result in an efficiency improvement of approximatelythirty percent as compared to the prior art.

It should be pointed out at this juncture that the device 20 asdescribed above is merely exemplary of various components andarrangements that can be used to achieve the ends of this invention.Moreover, while the device of this invention has been described in thecontext of use with inflatable emergency evacuation devices, it shouldbe noted that that is merely exemplary. Thus, the device of thisinvention can be used with any inflatable device to inflate it. Thusdevices other than that specifically described above can be constructedin accordance with the teaching of this invention.

Without further elaboration the foregoing will so fully illustrate myinvention that others may, by applying current or future knowledge,adopt the same for use under various conditions of service.

I claim:
 1. A nozzle assembly for use in an aspirator assembly forinflating inflatable emergency evacuation devices, the aspiratorassembly including an ambient air inlet port, an outlet port, a mixingchamber, and a check valve, the mixing chamber defining a gas flow pathbetween the ambient air inlet port and the outlet port, said nozzleassembly having a longitudinal axis and comprising: a brace configuredfor mounting said nozzle assembly within the mixing chamber, said bracecomprising two linear sections which intersect perpendicularly to eachother to form a cross brace, each of said linear sections comprising twocoplanar half sections which are conjoined to each other, one of saidlinear sections including a first end and a second end, said first endincluding a threaded opening, said second end including a threadedopening, each of said threaded openings being configured for receipt ofa threaded fastener to mount said nozzle assembly within the mixingchamber, the other of said linear sections including a third end and afourth end, said third end including a threaded opening configured forreceipt of a threaded fastener to mount said nozzle assembly within themixing chamber; a primary gas inlet port located at said fourth end andconfigured to receive a pressurized primary gas; and a concentricring-like member comprising an outer ring and an inner ring, said innerring being located centered in said outer ring, each of said ringscomprising a plurality of conjoined passageway sections, said passagewaysections lying in a plane perpendicular to said longitudinal axis andhaving internal passageways in fluid communication with said primary gasinlet port for receipt of the pressurized primary gas therein, saidpassageway sections including plural nozzle jets, each of said nozzlejets being a hollow tubular member extending in a first directionparallel to said longitudinal axis and perpendicular to said plane andhaving an open free end spaced from said passageway sections, saidpassageway sections being of a generally symmetrical cambered top andbottom airfoil shape cross section comprising a rounded leading end anda tapering trailing end, said leading end being directed in a seconddirection opposite to said first direction, said trailing end beingdirected in said first direction, said nozzle assembly being configuredwhereupon when the pressurized primary gas is introduced into saidprimary gas inlet port the pressurized primary gas flows through saidinternal passageways to said nozzle jets from which it exits said openfree ends to create a venturi effect and partial vacuum adjacent saidnozzle jets to cause the check valve to open, whereupon ambient air isdrawn from the ambient air inlet port past said the check valve, intosaid the mixing chamber and out of said the outlet port.
 2. The nozzleassembly of claim 1, wherein each of said tubular members includes asidewall tapering in thickness toward said free end.
 3. The nozzleassembly of claim 1, wherein said primary gas inlet port comprises athreaded opening.
 4. The nozzle assembly of claim 1, wherein each ofsaid threaded openings is internally threaded.